A piezoelectric element may be used in a conventional printing head of an inkjet printer to effect a discharge of an ink drop in a printing operation. In a printing head of this type, the piezoelectric element is deformed by application of a drive voltage. A piezoelectric element deformation applies pressure to a reservoir of ink within an ink storing chamber (or ink channel) of the printing head, thus causing at least a portion of the reservoir to be discharged from a nozzle in communication with such reservoir. The discharged ink drop adheres to a printing medium to form an ink dot, wherein a plurality of such dots form an image.
As mentioned, the piezoelectric element is driven by an applied pulse voltage. After application of the pulse voltage and discharge of an ink drop from the nozzle, a secondary and unnecessary vibration is generated within that ink remaining within the portions of the ink channel and/or nozzle in contact with the piezoelectric element. Moreover, when an ink drop of a large diameter is discharged, since the volume of the ink drop is greater than the volume of an ink drop of a small diameter, the vibration of the ink inside the ink channel and/or the nozzle is greater than that in the case where the ink drop of a small diameter is discharged.
In a printing head employing a piezoelectric element, a next ink drop should be discharged only after the vibration of the ink settles. This practice serves to ensure the accuracy of the next ink drop diameter. For this reason, if an ink vibration is great, a longer period must necessarily lapse before the next ink drop is discharged, thus such delay contributes to a reduction in overall printing speed.